1. This is information that IACS adopted the revision 4 of Procedural Requirement No.29 (PR 29) for definition of date of "contract for construction" with a view to clarifying "minor design alterations" of a series of vessels under a single contract for construction as attached.

2. This revision of PR29 Procedural Requirement was adopted on 21 June 2007 with immediate effect.

3. Background and contents of this revision
(1) A series of vessel was defined in previous versions of PR29 as vessels built to the same approved plans under a single contract for construction. According to this clause, if any vessel or vessels of a series of vessel have minor design alterations which are subject to classification requirements, the vessels were not considered a series of vessel.

(2) There are design alterations such as additions or modifications of equipment or systems related to classification requirements, which do not change the vessel's hull structural design, but which result in change of approval plans. In this case, the vessel would not be considered a series of vessel under a single contract for construction and her contract date, therefore, would be replaced by the date when such design alterations are contracted between shipbuilder and owner.

(3) However, IACS recognized it inappropriate to require the vessel to comply with all the new classification requirements in effective due to such design alternations.

(4) PR29 was amended that in case vessels within a series have design alterations from the original design, the original date of contract for construction remain unchanged provided that;
- such alterations do not affect matters related to classification, or
- if the alterations are subject to classification requirements, these alterations are to comply with the classification requirements in effect on the date on which the alterations are contracted between the prospective owner and the shipbuilder or, in the absence of the alteration contract, c